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At least 865 records · Page 48

Using Cosmic Ray Muons to Assess Geological Characteristics in the Subsurface

This is a technical presentation that does not take into account contractual limitations or obligations under the Standard Contract for Disposal of Spent Nuclear Fuel and/or High-Level Radioactive Waste (Standard Contract) (10 CFR Part 961). For example, under the provisions of the Standard Contract, spent nuclear fuel in multi-assembly canisters is not an acceptable waste form, absent a mutually agreed to contract amendment.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Verification and Validation of START: A Spent Nuclear Fuel Routing and Decision Support Tool

This is a technical presentation that does not take into account contractual limitations or obligations under the Standard Contract for Disposal of Spent Nuclear Fuel and/or High-Level Radioactive Waste (Standard Contract) (10 CFR Part 961). For example, under the provisions of the Standard Contract, spent nuclear fuel in multi-assembly canisters is not an acceptable waste form, absent a mutually agreed to contract amendment.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Giant negative thermal expansion covering room temperature in nanocrystalline GaN{sub x}Mn{sub 3}

Nanocrystalline antiperovskite GaN{sub x}Mn{sub 3} powders were prepared by mechanically milling. The micrograin GaN{sub x}Mn{sub 3} exhibits an abrupt volume contraction at the antiferromagnetic (AFM) to paramagnetic (PM) (AFM-PM) transition. The temperature window of volume contraction (ΔT) is broadened to 50 K as the average grain size (〈D〉) is reduced to ∼30 nm. The corresponding coefficient of linear thermal expansion (α) reaches ∼ −70 ppm/K, which are comparable to those of giant NTE materials. Further reducing 〈D〉 to ∼10 nm, ΔT exceeds 100 K and α remains as large as −30 ppm/K (−21 ppm/K) for x = 1.0 (x = 0.9). Excess atomic displacements together with the reduced structural coherence, revealed by high-energy X-ray pair distribution functions, are suggested to delay the AFM-PM transition. By controlling 〈D〉, giant NTE may also be achievable in other materials with large lattice contraction due to electronic or magnetic phase transitions.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Well-observed dynamics of flaring and peripheral coronal magnetic loops during an M-class limb flare

In this paper, we present a variety of well-observed dynamic behaviors for the flaring and peripheral magnetic loops of the M6.6 class extreme limb flare that occurred on 2011 February 24 (SOL2011-02-24T07:20) from EUV observations by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory and X-ray observations by RHESSI. The flaring loop motion confirms the earlier contraction-expansion picture. We find that the U-shaped trajectory delineated by the X-ray corona source of the flare roughly follows the direction of a filament eruption associated with the flare. Different temperature structures of the coronal source during the contraction and expansion phases strongly suggest different kinds of magnetic reconnection processes. For some peripheral loops, we discover that their dynamics are closely correlated with the filament eruption. During the slow rising to abrupt, fast rising of the filament, overlying peripheral magnetic loops display different responses. Two magnetic loops on the elbow of the active region had a slow descending motion followed by an abrupt successive fast contraction, while magnetic loops on the top of the filament were pushed outward, slowly being inflated for a while and then erupting as a moving front. We show that the filament activation and eruption play a dominant role in determining the dynamics of the overlying peripheral coronal magnetic loops.

79 ASTRONOMY AND ASTROPHYSICS↗

In-situ Dehydration Studies of Fully K- Rb- and Cs-exchanged Natrolites

In-situ synchrotron X-ray powder diffraction studies of K-, Rb-, and Cs-exchanged natrolites between room temperature and 425 C revealed that the dehydrated phases with collapsed frameworks start to form at 175, 150, and 100 C, respectively. The degree of the framework collapse indicated by the unit-cell volume contraction depends on the size of the non-framework cation: K-exchanged natrolite undergoes an 18.8% unit-cell volume contraction when dehydrated at 175 C, whereas Rb- and Cs-exchanged natrolites show unit-cell volume contractions of 18.5 and 15.2% at 150 and 100 C, respectively. In the hydrated phases, the dehydration-induced unit-cell volume reduction diminishes as the cation size increases and reveals increasingly a negative slope as smaller cations are substituted into the pores of the natrolite structure. The thermal expansion of the unit-cell volumes of the dehydrated K-, Rb-, and Cs-phases have positive thermal expansion coefficients of 8.80 x 10{sup -5} K{sup -1}, 1.03 x 10{sup -4} K{sup 01}, and 5.06 x 10{sup -5} K{sup -1}, respectively. Rietveld structure refinements of the dehydrated phases at 400 C reveal that the framework collapses are due to an increase of the chain rotation angles, {Psi}, which narrow the channels to a more elliptical shape. Compared to their respective hydrated structures at ambient conditions, the dehydrated K-exchanged natrolite at 400 C shows a 2.2-fold increase in {Psi}, whereas the dehydrated Rb- and Cs-natrolites at 400 C reveal increases of {Psi} by ca. 3.7 and 7.3 times, respectively. The elliptical channel openings of the dehydrated K-, Rb-, to Cs-phases become larger as the cation size increases. The disordered non-framework cations in the hydrated K-, Rb-, and Cs-natrolite order during dehydration and the subsequent framework collapse. The dehydrated phases of Rb- and Cs-natrolite can be stabilized at ambient conditions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Structural Studies of NH4-exchanged Natrolites at Ambient Conditions and High Temperature

We report here for the first time that fully and partially NH{sub 4}-exchanged natrolites can be prepared in hydrated states using the solution exchange method with potassium-natrolite. The structural models of the as-prepared hydrated phases and their dehydrated forms at elevated temperature were refined in space group Fdd2 using in situ synchrotron X-ray powder diffraction data and Rietveld methods. The unit-cell volumes of the hydrated NH{sub 4}-exchanged natrolites at ambient conditions, (NH{sub 4}){sub 16(2)}Al{sub 16}Si{sub 24}O{sub 80}{center_dot}14.1(9)H{sub 2}O and (NH{sub 4}){sub 5.1(1)}K{sub 10.9(1)}Al{sub 16}Si{sub 24}O{sub 80}{center_dot}15.7(3)H{sub 2}O, are found to be larger than that the original sodium-natrolite by ca. 15.6% and 12.8%, respectively. Upon temperature increase, the fully NH{sub 4}-exchanged natrolite undergoes dehydration at ca. 150 C with ca. 16.4% contraction in the unit-cell volume. The dehydrated phase of the fully NH{sub 4}-exchanged natrolite exhibits marginal volume expansion up to 425 C and then becomes amorphized during temperature decrease and exposure to atmospheric condition. In the case of the partially NH{sub 4}-exchanged natrolite, the dehydration starts from ca. 175 C with {approx}15.1% volume contraction and leads to a partial phase separation to show a phase related to the dehydrated K-natrolite. The degree of the phase separation decreases with temperature increase up to 475 C, concomitant to the gradual volume contraction occurring in the partially NH{sub 4}-exchanged natrolite in the dehydrared state. Upon temperature decrease and exposure to atmospheric condition, only the dehydrated K-natrolite is recovered as a crystalline phase from the partially NH{sub 4}-exchanged natrolite. In the hydrated model of the fully NH{sub 4}-exchanged natrolite, the ammonium cations and water molecules are statistically distributed along the elliptical channels, similar to the disordered pattern observed in natrolites exchanged with larger alkali metal cations such as the K-, Rb-, and Cs-forms. The dehydrated model of the fully NH{sub 4}-exchanged natrolite at 400 C is essentially same as the one reported previously from the sample prepared by direct melt exchange method using sodium-natrolite. Both the hydrated and dehydrated structures of the partially NH{sub 4}-exchanged natrolite at RT and at 400 C, respectively, are characterized by having two separate sites for the ammonium and potassium cations. Comparing the structural models of the monovalent cation forms studied so far, we find that the rotation angle of the natrolite chain is inversely proportional to the cation radius both in the hydrated and dehydrated phases. The distribution pattern of the non-framework species along the natrolite channel also seems to be related to the non-framework cation radius and hence to the chain rotation angle.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Reported Energy and Cost Savings from the DOE ESPC IDIQ Program: FY 2024

Energy Savings Performance Contracts (ESPCs)are a contractual mechanism that allow a federal agency to procure energy savings and facility improvements without upfront capital costs to reduce costs and resiliency. ESPCs are covered under FAR Part 23.2, and 42 USC § 8287. Section 8287(a)(2)(A) of Title 42 of the U.S. Code requires that each energy savings performance contract (ESPC) undergo an annual energy audit, resulting in a separate audit report for every project. The objective of the present report is to compile and analyze all annual ESPC audit reports issued between October 1, 2023, and September 30, 2024, for projects awarded under Generations 1, 2, and 3 of DOE’s ESPC IDIQ contracts. During this period, 205 measurement and verification (M&V) reports were produced for 200 projects; the total number of reports exceeds the number of projects because some projects generated more than one report(for example, a few projects measure savings twice per year and produce two audit reports annually, each covering a different six-month period). By aggregating the results from these individual audits, the report determines the portfolio-wide realization rate of energy and cost savings for all active ESPC projects awarded under DOE’s IDIQ program. For all 205audit reports, sufficient information was available to compare project-level estimated, reported, and guaranteed cost savings. Reported cost savings accounted for ESCO verified savings per each project’s M&V plan. The total reported cost savings for the period addressed were $\$$647.8million,compared with the total guaranteed cost savings of $\$$601.6million. On average across the reported projects: •ESPC contractors guaranteed 92.8% of the estimated cost savings• projects reported achieving 100.0% of the estimated cost savings• projects reported achieving 107.7% of the guaranteed cost savings. The M&V performed for the period indicated adjustments for government operations and maintenance impacts to savings amount to$\$$43.9millionandcould be restored with the original operational parameters for impacted projects. Accounting for this potential cost savings impact, these projects still realized 100.4% of the guaranteed cost savings. The information on estimated and reported energy savings was collected and compared for all 205of the reports examined. Based on site energy, estimated savings totaled 14.88million MMBtu, and reported savings were 15.33million MMBtu; 3.1% greater than the estimated energy savings. All of the reports examined contained sufficient information to calculate source energy savings. Based on site-adjusted source energy, total estimated energy savings were 20.90 million MMBtu, and reported savings were 21.22million MMBtu, 101.5% of the estimated energy savings. For water savings, the estimated savings were 11,539,055 kGal and the reported savings were 13,315,930 kGal. This means 1,776,875 kGal more water was saved than estimated, which is about 15% higher than the estimate. These results indicate that, overall, the reported energy savings slightly exceeded the estimated values, while estimated water savings significantly exceeded estimated values, suggesting that the projects achieved greater cost savings than originally projected. The total annual expense for the ESCOs to perform annual M&V audits and reporting was $\$$10.02million. Through this effort, $\$$647.8 million in annual cost savings was verified. The M&V results indicated that $\$$43.9 million of these verified savings reflected adjustments due to government operations A-6and maintenance impacts, which could be restored under the original operational parameters for the affected projects. These findings show the value of M&V that only costs 1.7%of the guaranteed cost savings to ensure guarantees are met.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Effects of space flight on the immunohistochemical demonstration of connexin 26 and connexin 43 in the postpartum uterus of rats

The effect of space flight in a National Aeronautics and Space Administration shuttle was studied in pregnant rats. Rats were launched on day 11 of gestation and recovered on day 20 of gestation. Pregnancy was allowed to proceed to term and rats delivered vaginally on days 22-23, although flight animals required more labour contractions to complete the delivery process. Pups were placed with foster dams and connexin 26 and 43 were examined in the uterus of flight animals approximately 3 h after delivery. Space flight did not affect uterine connexin 26, localized primarily in epithelial cells of the endometrium, but decreased connexin 43, the major gap junction protein in the myometrium. It is suggested that decreased connexin 43 alters synchronization and coordination of labour contractions, resulting in a requirement for more contractions to complete the delivery process.

Non-NASA Center↗

Early Regulatory Engagement for Successful Site Remediation: the UK Experience - 13173

The Office for Nuclear Regulation (ONR) is an independent safety, security and transport regulator of the UK nuclear industry. ONR regulates all civil nuclear reactor power stations, fuel manufacture, enrichment, spent fuel reprocessing, most defence sites and installations that store and process legacy spent fuel and radioactive waste. The responsibility for funding and strategic direction of decommissioning and radioactive waste management of state owned legacy sites has rested solely with the Nuclear Decommissioning Authority (NDA) since 2005. A key component of NDA's mandate was to encourage new strategic approaches and innovation to dealing with the UK's waste legacy and which deliver value-for-money to the UK taxpayer. ONR, as an agency of the Health and Safety Executive, is entirely independent of NDA and regulates all prescribed activities on NDA's sites. NDA's competition of site management and closure contracts has attracted significant international interest and the formation of consortia comprised of major British, US, French and Swedish organizations bidding for those contracts. The prominence of US organizations in each of those consortia reflects the scale and breadth of existing waste management and D and D projects in the US. This paper will articulate, in broad terms, the challenges faced by international organizations seeking to employ 'off-the-shelf' technology and D and D techniques, successfully employed elsewhere, into the UK regulatory context. The predominantly 'goal-setting' regulatory framework in the UK does not generally prescribe a minimum standard to which a licensee must adhere. The legal onus on licensees in the UK is to demonstrate, whatever technology is selected, that in its applications, risks are reduced 'So Far As Is Reasonably Practicable' or 'SFAIRP'. By the nature of its role, ONR adopts a conservative approach to regulation; however ONR also recognises that in the decommissioning (and ultimately the site closure) domain, it is often necessary to consider and support novel approaches to achieve the nationally desired end-state. Crucial to successful and compliant operation in this regulatory environment is early and sustained engagement of the contractor with the regulator. There must be a 'no-surprises' culture to engender regulatory confidence early in a project. The paper considers some of the challenges facing international prime and lower tier contractors when undertaking D and D contracts in the UK, and emphasizes the importance of constructive and transparent dialogue with all regulators to sustain confidence at all stages of a major decommissioning project. The paper will also articulate ONR's strategy to increase collaboration with the US Department of Energy in light of increasing UK-US synergy in the area of waste management and to benchmark respective regulatory approaches. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Managing Waste Inventory and License Limits at the Perma-Fix Northwest Facility to Meet CH2M Hill Plateau Remediation Company (CHPRC) American Recovery and Reinvestment Act (ARRA) Deliverables - 12335

CH2M Hill Plateau Remediation Company (CHRPC) is a prime contractor to the U.S. Department of Energy (DOE) focused on the largest ongoing environmental remediation project in the world at the DOE Hanford Site Central Plateau, i.e. the DOE Hanford Plateau Remediation Contract. The East Tennessee Materials and Energy Corporation (M and EC); a wholly owned subsidiary of Perma-Fix Environmental Services, Inc. (PESI), is a small business team member to CHPRC. Our scope includes project management; operation and maintenance of on-site storage, repackaging, treatment, and disposal facilities; and on-site waste management including waste receipt from generators and delivery to on-site and off-site treatment, storage, and disposal facilities. As part of this scope, M and EC staffs the centralized Waste Support Services organization responsible for all waste characterization and acceptance required to support CHPRC and waste generators across the Hanford Site. At the time of the CHPRC contract award (August 2008) slightly more than 9,000 cubic meters (m{sup 3}) of legacy waste was defined as 'no-path-forward waste'. A significant portion of this waste (7,650 m{sup 3}) comprised wastes with up to 50 grams of special nuclear materials (SNM) in oversized packages recovered during retrieval operations and large glove boxes removed from the Plutonium Finishing Plant (PFP). Through a collaborative effort between the DOE, CHPRC, and Perma-Fix Environmental Services, Inc. (PESI), pathways for these problematic wastes were developed that took advantage of commercial treatment capabilities at a nearby vendor facility, Perma-Fix Northwest (PFNW). In the spring of 2009, CHPRC initiated a pilot program under which they began shipping large package, low gram suspect TRU (<15 g SNM per container), and large package contact and remote handled MLLW to the off-site PFNW facility for treatment. PFNW is restricted by the SNM limits set for the total quantity of SNM allowed at the facility in accordance with the facility's radioactive materials license(s) (RML). While both CHPRC and PFNW maintain waste databases to track all waste movements, it became evident early in the process that a tool was needed that married the two systems to better track SNM inventories and sequence waste from the point of generation, through the PFNW facility, and back to the Hanford site for final disposition. This tool, known as the Treatment Integration and Planning Tool (TIPT), has become a robust planning tool that provides real-time data to support compliant and efficient waste generation, transportation, treatment, and disposition. TIPT is developing into the next generation tool that will change the way in which legacy wastes, retrieval wastes and decontamination and decommissioning operations are conducted on the Plateau Remediation Contract (PRC). The real value of the TIPT is its predictive capability. It allows the W and FMP to map out optimal windows for processing waste through the PFNW facility, or through any process that is in some way resource limited. It allows project managers to identify and focus on problem areas before shipments are affected. It has been modified for use in broader applications to predict turnaround times and identify windows of opportunity for processing higher gram wastes through PFNW and to allow waste generators, site-wide, to accurately predict scope, cost, and schedule for waste generation to optimize processing and eliminate storage, double handling, and related costs and unnecessary safety risks. The TIPT addresses the years old problem of how to effectively predict not only what needs to be done, but when. 'When' is the key planning parameter that has been ignored by the generator and processor for many years, but has proven to be the most important parameter for both parties. While further refinement is a natural part of any development process, the current improvements on the TIPT have shown that prediction is a powerful consideration. Even in lean times expected for the foreseeable future, the improved TIPT continues to play a central role in managing our way through those times to assure facilities remain viable and available. It is recommended that other major remediation projects and waste processing facilities incorporate a tool such as TIPT to improve customer-commercial supplier communications and better optimization of resources. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

COMET: A Domain-Specific Compilation of High-Performance Computational Chemistry

The computational power increases over the past decades have greatly enhanced the ability to simulate chemical reactions and understand ever more complex transformations. Tensor contractions are the fundamental computational building block of these simulations. These simulations have often been tied to one platform and restricted in generality by the interface provided to the user. The expanding prevalence of accelerators and researcher demands necessitate a more general approach which is not tied to specific hardware or requires contortion of algorithms to specific hardware platforms. In this paper we present COMET, a domain-specific programming language and compiler infrastructure for tensor contractions targeting heterogeneous accelerators. We present a system of progressive lowering through multiple layers of abstraction and optimization that achieves up to 1.98×speedup for 30 tensor contractions commonly used in computational chemistry and beyond.

Mutlu, Erdal↗

Characterization of human lung cancer-associated fibroblasts in three-dimensional in vitro co-culture model

Highlights: Black-Right-Pointing-Pointer We established three patient-paired sets of CAFs and NFs. Black-Right-Pointing-Pointer CAFs and NFs were analyzed using three-dimensional co-culture experiments. Black-Right-Pointing-Pointer CAFs clearly enhanced collagen gel contraction. Black-Right-Pointing-Pointer CAFs showed higher {alpha}-SMA expression than NFs. Black-Right-Pointing-Pointer CAFs were implicated in invasion and differentiation of lung cancer cells. -- Abstract: Lung cancer is the most common cause of cancer-related death worldwide. Stromal cancer-associated fibroblasts (CAFs) play crucial roles in carcinogenesis, proliferation, invasion, and metastasis of non-small cell lung carcinoma, and targeting of CAFs could be a novel strategy for cancer treatment. However, the characteristics of human CAFs still remain to be better defined. In this study, we established patient-matched CAFs and normal fibroblasts (NFs), from tumoral and non-tumoral portions of resected lung tissue from lung cancer patients. CAFs showed higher {alpha}-smooth muscle actin ({alpha}-SMA) expression than NFs, and CAFs clearly enhanced collagen gel contraction. Furthermore, we employed three-dimensional co-culture assay with A549 lung cancer cells, where CAFs were more potent in inducing collagen gel contraction. Hematoxylin and eosin staining of co-cultured collagen gel revealed that CAFs had the potential to increase invasion of A549 cells compared to NFs. These observations provide evidence that lung CAFs have the tumor-promoting capacity distinct from NFs.

60 APPLIED LIFE SCIENCES↗

Mitoflash lights single mitochondrial dynamics events in mature cardiomyocytes

Mitochondria, the powerhouse of eukaryotic cells, are highly dynamic organelle. Mitochondrial fission, fusion, kissing and contraction have been reported over and over again in non-static cells, such as fibroblast, with tubular mitochondrial networks. Even though the fluorescence propagation among mitochondria of mature cardiomyocytes had been captured using mitochondrial matrix targeted photoactivatable GFP (PAGFP) or MitoDendra proteins, there are no direct evidence that single real time mitochondrial dynamics events exist in mature cardiomyocytes with ball-like mitochondria. Here we first time revealed the visualizable single mitochondrial dynamics events in adult mature cardiomyocytes by the mitochondrial flash (mitoflash). We found fission, fusion, contraction and kissing were accompanied by a mitoflash event. Metabolism could increase mitochondrial contraction. Fusion and Kissing mediated inter-mitochondrial communication with higher frequency than fission. These results demonstrate that mitochondria of static mature cardiomyocytes are undergoing the rare, but real dynamics change.

60 APPLIED LIFE SCIENCES↗

Enhanced calcium entry via activation of NOX/PKC underlies increased vasoconstriction induced by methylglyoxal

Advanced glycation end-products (AGEs) play a pivotal role in macro- and micro-vascular diabetic complications. We investigated the mechanism by which methylglyoxal (an endogenous generator of AGEs) affects vascular contractility using the isolated artery technique. Contractile responses to vasoconstrictors phenylephrine (PE), angiotensin II (Ang II), vasopressin (VP) and KCl were measured in the isolated rat aorta following one-our exposure to methylglyoxal (50–200 μM). The perfused rat kidney was employed to confirm the effect of methylglyoxal on microvessels. Methylglyoxal-induced changes in cytosolic calcium were measured in the smooth muscle layer of the aorta with the calcium-sensing fluorophore Fluo-4 AM. Methylglyoxal significantly increased maximal contraction of the rat aorta to PE, Ang II and VP. Similar results were seen in response to the depolarizing vasoconstrictor KCl in macro and micro vessels. The methylglyoxal-induced increases in aortic contraction mediated by the agonist and KCl were endothelium independent. Methylglyoxal-induced increases in KCl-dependent aortic contraction were abolished after the removal of extracellular calcium or in the presence of the calcium channel blocker nifedipine. Incubation with the antioxidant N-acetyl-l-cysteine (NAC), apocynin (a nonselective NADPH oxidase (NOX) inhibitor) or chelerythrine (a protein kinase C (PKC) inhibitor) prior to methylglyoxal pre-treatment reversed the methylglyoxal-induced increases in the rat aortic contractility. In conclusion, the formation of AGEs increases vasoconstriction of both macro- and micro-vessels by increasing the voltage-activated calcium entry in vascular smooth muscles in a NOX and PKC dependent manner.

60 APPLIED LIFE SCIENCES↗

Analysis of the thermal-mechanical redox stability of Nb 2 TiO 7 and Nb 1.33 Ti 0.67 O 4 for SOFC application

Nb 2 TiO 7 and Nb 1.33 Ti 0.67 O 4 was reported as a potential anode materials for Solid Oxide Fuel Cells (SOFCs) based on their stable reversible phase transformation and high electronic conductivity. A high-temperature redox dilatometry test was developed to monitor the linear expansion or contraction of Nb 2 TiO 7 and Nb 1.33 Ti 0.67 O 4 synthesized through a solid-state route. XRD analysis confirmed the phase purity. It was found that Nb 2 TiO 7 contracts linearly up to 0.006% in a reducing atmosphere and this contraction is reversible in nature whereas Nb 1.33 Ti 0.67 O 4 expands linearly up to 1.9% in an oxidizing atmosphere which is irreversible in nature at 800 °C. In addition, the electrical conductivity of the materials was analyzed in redox atmospheres. At 800 °C, Nb 2 TiO 7 showed an electrical conductivity of 1.35 S/cm in forming gas (5%H 2 /95%N 2 ) which increases to 85 S/cm upon the reduction of Nb 2 TiO 7 to Nb 1.33 Ti 0.67 O 4 .Here this study emphasizes the importance of high-temperature redox dilatometry in the development of SOFC electrode materials.

36 MATERIALS SCIENCE↗

Cardiac Motion During Deep-Inspiration Breath-Hold: Implications for Breast Cancer Radiotherapy

Purpose: Many patients with left-sided breast cancer receive adjuvant radiotherapy during deep-inspiration breath hold (DIBH) to minimize radiation exposure to the heart. We measured the displacement of the left anterior descending artery (LAD) and heart owing to cardiac motion during DIBH, relative to the standard tangential fields for left breast cancer radiotherapy. Methods and Materials: A total of 20 patients who had undergone computed tomography-based coronary angiography with retrospective electrocardiographic gating were randomly selected for the present study. The patients underwent scanning during DIBH to control the influence of respiration on cardiac motion. Standard medial and lateral tangential fields were placed, and the LADs were contoured on the systolic- and diastolic-phase computed tomography data sets by the clinicians. Displacement of the LAD during cardiac contractions was calculated in three directions: toward the posterior edge of the treatment fields, left-right, and anteroposterior. Displacement of the entire heart was measured on the maximal and minimal intensity projection computed tomography images. Results: The mean displacement of the LAD from cardiac contraction without the influence of respiration for 20 patients was 2.3 mm (range, 0.7-3.8) toward the posterior edge of the treatment fields, 2.6 mm (range, 1.0-6.8) in the left-right direction, and 2.3 mm (range, 0.6-6.5) in the anteroposterior direction. At least 30% of the LAD volume was displaced >5 mm in any direction in 2 patients (10%), and <10% of the LAD volume was displaced >5 mm in 10 patients (50%). The extent of displacement of the heart periphery during cardiac motion was negligible near the treatment fields. Conclusions: Displacement of the heart periphery near the treatment fields was negligible during DIBH; however, displacement of the LAD from cardiac contraction varied substantially between and within patients. We recommend maintaining {>=}5 mm of distance between the LAD and the field edge for patients undergoing breast cancer radiotherapy during DIBH.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Scaling up the energy service company business: market status and company feedback in the Russian Federation

Many energy efficiency professionals have proposed using Energy Performance Contracts (EPCs) as a mechanism to improve public sector energy efficiency in countries with restrictive government budgets. However, in practice, most middle-income countries have used this mechanism only in a limited way. Russia offers an interesting case study because of its huge energy savings opportunities, increasing energy prices, robust political backing for public sector energy efficiency, and evolving legislation that supports EPCs. In 2009, the Russian Federation launched a program to reduce the energy intensity of the country’s large public sector, which accounts for 9 percent of Russia’s total energy consumption. To achieve energy efficiency goals, Russia experimented with its public procurement rules, adjusting them to encourage EPCs. We conducted structured interviews with Energy Service Companies (ESCOs) in Russia and supplemented them with online research. Our review shows that, to date, nearly 50 ESCOs signed about 150 contracts in public facilities. Most ESCO contracts in Russia are for 5 years, and they generally are small (under $100,000). ESCOs in Russia face a challenging environment, which leads to smaller projects. ESCOs also are concerned about costly and risky tender procedures, uncertainty regarding repayment from public facilities, the inability to expand projects, and financing. We discuss these challenges and propose potential solutions at policy and company levels. The ESCOs feedback regarding Russia’s experimental model can inform the country’s program for public sector energy efficiency and offer lessons for other countries attempting to develop the EPC mechanism.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗